Reaction propulsion system



Jan. 7, 1969 A. J. SAMUEL REACTION PROPULSION SYSTEM Sheet Filed Oct. 17, 1966 wm Om @N 0: Al m v Q #Q Q om \Nm Q0. l @N 3 .g 8 I 1 @9 7m: 2 m Nm @w w A um. ww mm qm 1 O mm NA. 5 ww 3 mm @m 5 w uwv m H .HH!

INVENTOR. ALAN J. SAMUEL ATTORNEY 7, 969 A. J. SAMUEL 3,420,204

REACTION PROPULS I ON SYSTEM Filed Oct. 17, 1966 Sheet 3 of 5 92 fig;

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ALAN .1. SAMUEL ATTORNEY Jan. 7, 1969 A. J. SAMUEL 3,420,204

REACTION PROPULSION SYSTEM I Filed Oct. 17, 1966 Sheet 4 of INVENTOR.

ALAN .1. SAMUEL JW M AT TORNE Y Jan. 7, 1969 A. J. SAMUEL REACTION PROPULSION SYSTEM Sheet 5 Filed Oct. 17, 1966 F'II3 1l:l

F'I I3 11,

INVENTOR.

ALAN J. SAMUEL AT TORNE Y United States Patent 3,420,204 REACTION PROPULSION SYSTEM Alan J. Samuel, San Jose, Calif., assignor to FMC Corporation, San Jose, Calif., a corporation of Delaware Filed Oct. 17, 1966, Ser. No. 587,014 US. Cl. 1151 6 Claims Int. Cl. B60f 3/00; 1363b 11/08; B6311 11/10 ABSTRACT OF THE DISCLOSURE An amphibious military vehicle having crawler tracks and hull portions termed sponsons overlying the tracks is provided with a rearwardly discharging water jet propulsion unit in each sponson, and an individually operable swinging gate or deflector for each jet to selectively aim the jets laterally away from the hull for steering. Induction water to the pumps travels upward through the upper reach of each crawler track into a suction chamber formed in the superposed sponson. A second embodiment of the invention uses a pair of swinging gates in each propulsion unit. Both embodiments are capable of marine propulsion and steering with only one pump operating.

The present invention pertains to amphibious vehicles, and more particularly concerns a marine propulsion system for a tracked military vehicle.

In the past, amphibious military vehicles equipped with crawler tracks have employed special track links to propel the vehicle both in the water and on land. Obviously, such dual purpose track links cannot achieve maximum efiiciency for either purpose, and are inefficient during water operation because while one flight of the track provides propulsion, the other flight moves in the opposite direction and counteracts part of the propulsive effect. Some vehicles have utilized propellers and conventional land track links, but require complex separate drive trains, including many gears and other controls, for each propulsion system. Further, the propellers of the latter type of vehicle are relatively vulnerable because they are outside the hull of the vehicle.

The present invention provides an improved propulsion system, for a military amphibious vehicle equipped with crawler tracks, by employing water jets for marine propulsion which are so arranged and controlled that the vehicle achieves highly efficient maneuverability in the water and has crawler tracks designed for near optimum efiiciency during land propulsion.

Accordingly, an object of the present invention is to provide an improved marine propulsion system for an amphibious tracked vehicle.

Another object of the invention is to provide a marine propulsion system for an amphibious tracked vehicle wherein the components of the system are completely within the hull and are to a great extent invulnerable.

Another object is to provide an inboard marine propulsion unit which has a high propulsive efiiciency, yet is relatively compact so as to allow maximum use of the hull for cargo.

Another object is to provide a marine propulsion and steering system for an amphibious vehicle which provides a high static thrust efliciency.

Another object is to provide a marine propulsion arrangement in which the drive train rotation is the same for forward and reverse movement of the hull, in contrast to propeller drive systems wherein the propeller and its drive shaft must be reversed to change the direction of movement of the hull.

Another object is the provision of a water jet propulsion and steering system which is capable of effecting precise steering-propulsion of a tracked amphibious vehicle.

A more specific object of the invention is to provide a steering and propulsion system, for an amphibious vehicle, which includes two water jet reaction units that are controlled to individually turn, reverse and provide forward thrust for the vehicle.

A further object is the provision of a water jet reaction propulsion unit with integral steering control, which by a particular structural arrangement is of minimal size, for a given thrust output, and achieves rapid steering response.

Another object is to provide a water jet steering and propulsion system, for an amphibious tracked vehicle, wherein the reaction unit lies in a sponson, and the suction inlet of the pump is located at the bottom of the sponson and in overlying, spaced relation to the associated vehicle track whereby the track, being perforate, screens the water before induction to the pump.

Further objects and advantages of the present invention will become apparent from the following specification and accompanying drawings, wherein:

FIGURE 1 is a diagrammatic plan of an amphibious military vehicle, and is partly broken away to reveal the water jet reaction propulsion system of the present invention.

FIGURE 2 is a diagrammatic side elevation, partly broken away, of the vehicle shown in FIGURE 1.

FIGURE 3 is a diagrammatic section taken along lines 3-3 on FIGURE 2.

FIGURE 4 is an enlarged diagrammatic perspective of a water jet reaction unit indicated by the arrow 4 on FIGURE 1.

FIGURES 5, 6 and 7 are diagrammatic operational plan views of the water jet reaction unit shown in FIG- URE 4.

FIGURE 8 is a diagrammatic plan, similar to FIG- URE l and broken away in like manner, of a second embodiment of the water jet reaction propulsion system as employed in a larger type of amphibious vehicle than the vehicle shown in FIGURE 1.

FIGURE 9 is a diagrammatic side elevation, partly broken away, of the vehicle shown in FIGURE 8.

FIGURE 10 is an enlarged, diagrammatic horizontal section of the water jet propulsion unit taken along lines 1010 on FIGURE 9.

FIGURE 11 is a vertical diagrammatic section of a modified form of the FIGURE 10 propulsion unit.

FIGURE 12 is a diagrammatic perspective of the structure shown in FIGURE 10.

With general reference to FIGURES 1-3, a typical amphibious tracked military vehicle V includes a fabricated metal hull 20 having a bow 22 and a stem end or transom 26 provided with a central loading ramp door 24, controlled from a pilots station, not shown, near the bow. Inwardly of an outer side plate 28 of the hull 20 and near each port and starboard end of the transom or transverse stern portion 26, a water jet discharge outlet 30 is provided. A reaction propulsion unit 32 is aligned with each outlet 30 for generating and discharging a substantially columnar flow jet of water toward the outlet. According to the present invention, the structural arrangement and control of the propulsion units 32 provides a heretofore unattained precise marine maneuverability and propulsion etficiency for an amphibious tracked vehicle.

With continued and more specific reference to FIG- URES 1-3, an endless track 34 for ground propulsion is trained around drive and bogey wheels 36 at each side of the vehicle. The superposed or sponson portion of the hull extending over each upper track flight 38 is provided with a discontinuous lower wall 40 which, between upright end walls 42 and 44, is open over the upper track flight 38 to provide a water inlet area 46. The lateral extent of the water inlet area 46 is between an inner wall 48 of the hull and a skirt 50 which depends from the outer side plate 28. The walls 40 and 48 and the skirt 50 provide an open-ended, elongate water channel 52 extending over the upper track flight 38, the track being perforate so that water can pass upward through and between the links of the upper track flight 38 both forward, below and aft of the water inlet at 46. The horizontal clearance between the edges of the track and the adjacent walls is relatively small and will also screen water which flows up toward the channel 52. The vertical distance between the lower wall 40 and the upper track flight 38 increases when the vehicle is floating, because the suspension for the bogey wheels 36 becomes slack, thus assuring minimal restriction of water flowing in the channel 52 to the water inlet at 46.

In the case of the illustrated vehicle V, the water inlet area 46 is approximately two feet wide and seven feet long, and has an upper wall 54 sloping downward from about two feet at the end wall 44, to about one foot at the end wall 42. While these dimensions only indirectly concern the invention, the point to be noted is that the propulsion unit 32 and its water inlet area 46 are elongated and narrow. Thus, the lateral dimension of items 32 and 46 is such as to minimize encroachment of the cargo space within the hull, and the water inlet area can be proportioned to provide any required input capacity by extending or shortening its length.

A further advantage of this structural arrangement is clearly shown in FIGURE 2 wherein the starboard propulsion unit 32 is seen to tilt downward toward the bow 22, and the chamber 56 above the water inlet 46 tapers downward in the same direction. When a vehicle of this type is moving through the water, it generates a dynamic water line DWL including a bow wave indicated at 58, followed by a trough at 60 and succeeded by a swell 62. It will be seen that the upper profile of the propulsion unit 32 and the chamber 56 lie below the profile of the swell, and as a result are less vulnerable to lateral puncture of the hull than if they projected upward beyond the dynamic water line.

Each propulsion unit 32 (FIG. 4) comprises a conventional high eificiency rotary pump 64 having a circular housing. Both pumps are simultaneously driven. The inlet bell 65 of the pump encircles an inlet aperture 68 (FIG. 3) in the end wall 44, and has a fluid tight seal to the end wall. A driveshaft 66 extends forwardly from the pump 64 through the inlet aperture 68, through the end wall 42, and is coupled to a universal joint 70 that is driven from the same power source that drives the tracks 34. If the tracks are designed for optimum efficiency in land propulsion, there is no advantage to be gained by driving the tracks when the marine propulsion units are operating. Accordingly, the drive trains for the tracks and the marine propulsion units are selectively driven, by employing suitable clutches and other controls, not shown, so that the land and marine drive means are each capable of optimum efficiency for their particular use.

The pump 64 (FIG. 4) merges into a discharge nozzle 72, one advantage of which is that an associated water jet deflector 74 canbe nested over the nozzle and positioned closer to the inlet end of the pump. The pump and nozzle housing 64, being of one piece construction, minimizes the overall length of the propulsion unit 32, in contrast to a separate nozzle and pump housing arrangement. While a rectangular opening is shown for the nozzle 72, a round nozzle will serve as well. The rectangular type facilitates mounting of the water jet deflector 74.

A pivot stub shaft 76 projects upward from the pump and nozzle housing 64, and a similar shaft 77 (FIG. 2) is aligned with shaft 76 and projects downward from the housing. The pivot shafts respectively pivotally mount top and bottom arms 78 and 80 which have curved free edge portions that are joined together by an arcuate, upright flow diverter plate 82 arranged for movement across the flow path of water ejected from the discharge nozzle 72. Such movement is effected by a double-acting hydraulic steering power control cylinder 84 which is pivoted by a bracket 86 to the end wall 44, and the piston rod 87 of which is pivoted to a bracket 88 upstanding from the top arm 78; these parts lie beneath a top wall 90 which defines the upper limit of the compartment housing the propulsion unit 32. It will be apparent that the Water jet deflector 74 of the port propulsion unit 32 is of similar, but opposite construction, as clearly shown in FIGURE 1.

The edge 92 (FIG. 4) of the flow diverter plate 82, when the latter is in its FIGURES 4 and 5 fully retracted position, is completely out of the path of the jet, as best shown in FIGURE 5 wherein the flow arrows at 94 depict the flow path and general lateral extent of the jet. Since the flow path is parallel to the longitudinal axis of the vehicle, the resultant thrust for this particular propulsion unit 32 is for straight-ahead motion. FIGURE 7 shows the opposite extreme of movement for the water jet deflector 74, and FIGURE 6 shows an intermediate position; these positions are respectively for reverse thrust and steering. If the steering controls, not shown are actuated to extend the piston rod 87 (FIG. 5), the edge 92 of the flow diverter plate 82 impinges the water jet and the inner curved face of the flow diverter plate smoothly deflects the jet laterally outward from the vehicle, as indicated by the flow arrows 94 in FIGURE 6. A lateral thrust component is thus produced which urges the stern of the vehicle to port, and steers the vehicle toward the starboard side.

When the piston rod 87 (FIG. 7) of the steering control cylinder 84 is fully extended, the edge 92 of the flow diverter plate 82 contacts a terminal edge portion at 102 of the hull side plate 28. During such motion, the bottom arm 80 (FIG. 4) of the water jet deflector 74 slides under a bottom wall 104 of a reverse duct 106, and the upper arm 78 slides over a top wall 108 of the same duct. Other portions of the reverse duct 106 are formed by the inner surface of an inwardly sloping end portion 110 of the hull side plate 28, and by an inner side wall 112. The discharge end of the reverse duct 106 is a horizontally elongate aperture 114 in the hull side plate 28. In order to seal the inlet end of the reverse duct 106, the inner side wall 112 has an apertured inner portion 116 (FIG. 4) which encircles the discharge nozzle 72 and slidably engages the confronting surfaces of the arms 78 and 80. The wall 112 also projects inwardly beyond the nozzle to form an upright ledge 118 which engages the trailing portion of an inner curved surface 100 of the flow diverter plate 82 when the water jet deflector 74 is moved to its FIGURE 7 position. Accordingly, the thus confined jet is directed by the water jet deflector 74 into the reverse duct 106 and the flow path of the jet is in the direction of the arrows 94, forwardly relative to the vehicle, to effect a thrust reversal which will move the vehicle rearwardly if both propulsion units 32 are in reverse position. Steering in reverse will be accomplished when one of the deflectors 74 is partially opened from the BIG- URE 7 reverse position. Pivot steering will be eifected when one of the deflectors 74 is in the FIGURE 5 position, and the other deflector is in the FIGURE 7 position, whereby the vehicle will tend to turn substantially in place.

With continued reference to FIGURES 5-7, it will be apparent that the forward motion of the vehicle in the water will cause water to flow rearwardly through the reverse duct 106. This water, in the case of the straight forward thrust position shown in FIGURE 5, does not impair the efficiency of the jet because the lateral distance indicated at 119 between the lowermost flow arrow 94 and the adjacent terminal edge 102 of the side plate 28 allows free passage of the water passing through the reverse duct. When the water jet deflector 74 is in its FIG- URE 6 lateral thrust position, the reverse duct water mingles with the jet, but does not appreciably affect the efliciency of the jet. It is thus unnecessary to provide a valve in the reverse duct to stop water induction when the vehicle is moving forward.

FIGURES 8 and 9 illustrate an application of the water jet propulsion system of the present invention in a large amphibious transport vehicle V2 that is used for carrying military vehicles of the type indicated in FIGURES 1 and 2, or other cargo. The vehicle has port and starboard water jet reaction propulsion units 120 which are structurally modified from the similar units 32 already described, but are cooperatively arranged to function in the same diiferential steering manner to achieve marine propulsion and steering superior to that presently attained in military vehicles having both land and marine propulsion-steering effected by endless tracks.

The vehicle V2 includes a fabricated metal hull 122 having a how 124, a transome 126 (which includes a ramp, not shown) and hull side plates 128. Foating and fully loaded, the static water line is approximately as indicated by the line SWL, which roughly coincides with a cargo deck 130, below which is a hold 132. The propulsion units 120 are arranged at opposite end portions of the transom 126 and are individually supplied with water from pumps 134 that are mounted in the hold 132 inward of track assemblies 136 and below the cargo deck 130. Conduits 138, which each include two flexible sections 140 to facilitate alignment during installation, supply water from the pumps to the propulsion units, and pierce the deck 130 adjacent the nozzles to minimize encroachment of the cargo space above the deck.

Each pump 134 has a suction bell 142 which communicates with an aperture, not shown, in the bottom wall 144 of the hull 122 whereby water is induced to the pumps as indicated by the flow arrows 146. A clean-out riser 148, having a removable top cover which is accessible through a hatch in the deck 130, is a part of each suction bell 142. Coaxially arranged with each pump 134 is a driveshaft 150 which projects forward to a universal joint 152 that is connected to a shaft 154. Both shafts 154 are arranged to be simultaneously or independently driven by the same engines, not shown, which drive the track assemblies 136.

It should be mentioned here that this type of vehicle rides relatively high in the water, as evidenced by the freeboard of the hull above the static water line, and this prevents mounting the pumps 134 in the sponson area without providing priming means for the pumps. In the case of the vehicle V (FIGS. 1 and 2), the pumps are self priming, even though mounted high in the sponsons, because their axes of rotation are substantially below the static water line, even when unloaded.

FIGURES l0 and 12 illustrate the starboard propulsion unit 120, which includes a hollow housing having a rectangular chamber 156. The housing has a nozzle 158 removeably secured thereto and to a tapered end portion 160 of the conduit 138. Opposite the nozzle 158, the housing 156 has a rectangular outlet aperture 162 and merges into a steering section 164 that is defined by parallel upper and lower walls 166, and by rearwardly diverging side walls 168, including a pair of steering deflector vanes 184, later mentioned. The steering section terminates flush with the outer surface of the transom 126.

The rectangular chamber 156 communicates with a reverse duct 170 which extends diagonally forward and defines a horizontally elongate opening at 172 (FIG. 12) which is aligned with a corresponding opening 174 (FIG. in the hull side plate 128. A butterfly valve 173 is pivotally mounted on a shaft 175 in the duct 170 and is closed except when the propulsion unit 120 is providing reverse thrust.

FIGURE 11 shows a slightly different form of the FIG- URE 10 apparatus in which the reverse duct is indicated by the reference numeral 171 and discharges downward through the bottom wall 144 of the hull. Other than the bottom discharge reverse duct 171 and an integral nozzle 158, the FIGURE 11 structure can be considered a vertical section of the FIGURE 10 structure, and therefore carries the same reference numerals and employs the same butterfly valve 173.

An upright pivot shaft 176 extends through the upper and lower Walls 166 of the steering section 164, and the deflectors 184 are secured to the pivot shafts. Each pivot shaft is arranged to be rotated by a crank 178 that is powered by a double acting hydraulic power steering control cylinder 180. The hydraulic circuit, not shown, which energizes the cylinders 180 is controlled in a manner which includes the function of simultaneously actuating their piston rods 182 in opposite directions for steering control of the vehicle V2 when moving forward. Thus, one piston rod will be projected while the other is retracted. Another control function is the simultaneous projection of the piston rods in the same direction for reverse propulsion of the vehicle.

When both steering deflector vanes 184 are fully retracted by the cylinders 180, they attain the phantom line positions shown in FIGURE 10 and substantially seal the outlet aperture 162 so that the water is discharged laterally from the chamber 156 into the reverse duct 170. Coincident with such movement, separate control means turns the valve shaft so that the valve 173 does not obstruct the flow of water from the chamber 156. As in the FIG- URE 7 position, this water issues from the duct 170' in the direction of the phantom line arrows at 188, and the reaction thrust developed by reversing the normal flow of water drives the vehicle in a reverse direction when both pairs of steering deflectors 184 are in this position.

If the propulsion unit 120 has both steering deflectors 184 positioned as illustrated in FIGURE 10, the jet at 186 is unimpeded and the thrust is parallel to the longitudinal centerline of the vehicle to provide forward motion. A control signal from the pilot to turn the vehicle will move both pairs of steering deflectors in the same direction. Thus, a maximum turn will pivot one of the steering deflectors inward nearly to the phantom line position, and the other steering deflector will pivot outward close to the adjacent side wall 168. The thrust thus developed is comparable to that described in connection with FIGURE 6, and the vehicle will turn according to the direction and magnitude indicated by the control signal which energized the steering control cylinders 180.

While each of the propulsion units 120 will provide steering thrust in both lateral directions, and each of the propulsion units 32 provide thrust in only one direction, both systems utilize differential steering. However, a further advantage of the apparatus in FIGURES 10-l2 is that more precise steering can be provided in either direction with only one pair of steering deflectors. The control circuits for governing the steering control cylinders 84 and are not illustrated herein since they are well within the skill of persons versed in the art, and because they can embody various forms and are not properly a part of the present invention. In general, the control circuits may employ hydraulic servo valves to govern the direction in which the steering control power cylinders are energized, and selector valves to select the operational modes for each propulsion unit such as Forward, Neutral and Reverse.

By way of summarizing other novel features of the present invention, it is considered noteworthy that the propulsion units, in the absence of any steering control, have straight rearward thrust. Accordingly, if one or the other propulsion unit is damaged and inoperative, the other propulsion unit can steer and propel the vehicle. This is in direct contrast to propulsion systems of other known types wherein the vehicle becomes inoperative upon the failure of one of the propulsion units. Further, the propulsion system of the present invention is relatively invulnerable because all elements of the units are situated below the dynamic water line, and no components are exposed while the vehicles are under way. Since the suction inlets are relativelylow compared to the dynamic Water line, floating debris is not likely to be inducted into the pumps.

Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent that modification and variation may be made without departing from what is regarded to be the subject of the invention as set forth in the appended claims.

I claim:

1. A reaction propulsion system for an amphibious vehicle comprising a hull including a transom and upright side walls merging with the transom, said hull defining a longitudinally extending sponson along each side wall; a perforate endless crawler track disposed beneath each sponson, means defining a rearwardly open aperture adjacent each end portion of the transom, a jet nozzle mounted with its flow axis in endwise alignment wtih each aperture and extending along the adjacent side wall, a reaction-propulsion pump mounted in each sponson forward of the associated jet nozzle and connected in fluid communication with the nozzle for projecting a water jet under pressure rearwardly parallel to the longitudinal centerline of said hull, each of said sponsons including means defining a downwardly open water inlet chamber overlying the adjacent upper flight of said crawler track and communicating with the suction inlet of said pump whereby the induction water for the pumps is screened by the perforate tracks, flow deflecting means mounted Within each of said apertures adjacent the flow path of the associated water jet, said deflecting means being movable from a position remote from said flow path to provide straight-ahead thrust, to a position intercepting said water jet for providing lateral thrust by selectively aiming said jet laterally relative to the length of said hull, and an individually operable power actuated steering control connected to each of said flow deflecting means.

2. Apparatus according to claim 1 wherein the major portions of said pumps, said flow deflecting means and said nozzles are mounted in said hull below the dynamic water line generated when the vehicle is under way.

3. A reaction propulsion system for an amphibious vehicle having crawler tracks comprising a hull having side walls, a sponson extending longitudinally along each of said side Walls, a transom interconnecting said side walls, a perforate endless crawler track mounted beneath each sponson, each of said sponsons defining a downwardly open water inlet chamber overlying the adjacent upper flight of said crawler track, means defining an aperture adjacent each end portion of the transom, a jet nozzle mounted in said hull with its flow axis in endwise alignment with each aperture and parallel to the longitudinal centerline of the hull, and a reaction-propulsion pump connected to each nozzle, each pump having a suction inlet connected to the adjacent water inlet chamber so that the pump induction water is screened by the perforate track therebelow.

4. A reaction propulsion system for an amphibious vehicle comprising a hull including a longitudinally extending sponson along each side of the hull, a perforate endless crawler track disposed beneath each sponson, a jet nozzle mounted in each sponson with its flow axis parallel to the longitudinal centerline of said hull, a reaction-propulsion pump mounted in each sponson forward of the associated jet nozzle and connected with the nozzle for projecting a water jet rearwardly from said hull, each of said sponsons defining a downwardly open water inlet chamber overlying the adjacent upper flight of said crawler track, each inlet chamber communicating with the suction inlet of said pump whereby the induction water is screened by the perforate tracks, a flow deflector mounted adjacent the flow path of each water jet, said deflector being movable from a position remote from said flow path to provide straight-ahead thrust, to a position intercepting said water jet for providing lateral thrust by selectively aiming said jet laterally outward relative to the length of said hull, and an individually operable power actuated steering control connected to each of said flow deflectors.

5. An ampihibious vehicle comprising a hull having longitudinally extending sponsons along each side of the hull, a driven crawler track mounted under each sponson for providing land propulsion for said hull, a jet nozzle mounted aft at each side of said hull for marine propulsion, the flow axes of the nozzles being parallel to and equally spaced from the longitudinal centerline of the hull, a reaction-propulsion pump in fluid communication with each of said nozzles for projecting a water jet rearwardly through the nozzle, means defining an upwardly open suction chamber in each sponson above the adjacent upper reach of said crawler track, each of said chambers being connected to the inlet of its associated pump so that the induction water to the pump is screened by the subposed track flight.

6. The apparatus of claim 5 wherein the lateral dimension of said inlet chamber is substantially the same as the lateral dimension of the propulsion unit comprising said pump, said nozzle and said deflector, so as to occupy minimal interior hull space.

References Cited UNITED STATES PATENTS 3,198,161 8/1965 Andrews et a1. 1 XR 3,204,713 9/1965 Shanahan et al l151 FOREIGN PATENTS 1,261,430 4/1960 France.

ANDREW H. FARRELL, Primary Examiner.

US. Cl. X.R. 

